EU leaders are to meet to try to finalize a deal with Turkey to help ease the migrant crisis.
European Council President Donald Tusk admits a “Number of issues” in the way of an agreement remains unresolved.
The proposed plan would see all migrants arriving in Greece from Turkey sent back. For each Syrian returned, a Syrian in Turkey would be resettled in the EU.
German Chancellor Angela Merkel urged EU member states to do more.
“What Turkey has done for… Some 2.7 million refugees can’t be praised highly enough,” she told Germany’s parliament on Wednesday evening.
“Europe has not covered itself with glory in how, as a union of 28 members states with 500 million citizens, it has struggled with fairly sharing the burden.”
Last year, more than a million people entered the EU illegally by boat, mainly going from Turkey to Greece.
More than 132,000 migrants have arrived in Greece by boat so far this year – a large increase on the same period last year.